JP2025180182A - Electrical Connection Unit - Google Patents

Abstract

One embodiment provides an electrical connection unit that can provide improved thermal properties.
[Solution] In one embodiment, the electrical connection unit includes a first connection object, a second connection object, a base member, and a bus bar. The base member has a plate- or sheet-shaped planar portion facing the first connection object and the second connection object. The bus bar is held on the planar portion and electrically connects the first connection object and the second connection object. When the thickness direction of the planar portion is defined as a first direction, the planar portion has a housing portion that is recessed in the first direction or that penetrates the planar portion in the first direction. The bus bar includes a connection path portion and an extension portion. The connection path portion spans between the first connection object and the second connection object. The extension portion extends outward from the connection path portion and overlaps the first electronic component when viewed from the first direction.
[Selected Figure] Figure 7

Description

An embodiment of the present invention relates to an electrical connection unit.

An electrical connection unit is known that has a housing that contains electronic components and a bus bar attached to the housing in an upright position.

JP 2024-037492 A

By the way, electrical connection units are expected to have improved heat storage properties.

One embodiment provides an electrical connection unit that can improve heat storage capacity.

In one embodiment, the electrical connection unit has a first connection target, a second connection target, a base member, and a bus bar. The base member has a plate- or sheet-shaped planar portion facing the first connection target and the second connection target. The bus bar is held on the planar portion and electrically connects the first connection target and the second connection target. When the thickness direction of the planar portion is defined as a first direction, the planar portion has a housing portion that is recessed in the first direction or that penetrates the planar portion in the first direction. The bus bar has a connection path portion and an extension portion. The connection path portion spans between the first connection target and the second connection target. The extension portion extends outward from the connection path portion and overlaps the first electronic component when viewed from the first direction.

According to one embodiment, the thermal characteristics of the electrical connection unit can be improved.

FIG. 2 is a cross-sectional view showing the electrical connection unit according to the embodiment. FIG. 2 is a perspective view illustrating a main body of the embodiment. FIG. 2 is a perspective view illustrating a subunit according to the embodiment. FIG. 2 is a partially exploded perspective view of a subunit according to the embodiment. FIG. 2 is a perspective view showing the wiring board according to the embodiment. FIG. 2 is a partially exploded perspective view of the wiring board according to the embodiment. FIG. 2 is a plan view showing the wiring board according to the embodiment. FIG. 2 is a partially exploded perspective view of the electrical connection unit according to the embodiment. FIG. 8 is a cross-sectional view of the structure shown in FIG. 7 taken along line AA. FIG. 10 is a cross-sectional view showing a modified example of the embodiment. FIG. 10 is a cross-sectional view showing a modified example of the embodiment.

Embodiments will be described below with reference to the drawings. In the following description, components having the same or similar functions will be assigned the same reference numerals. Duplicate descriptions of these components may be omitted. Note that the configurations described below do not limit the scope of the embodiments.

In this disclosure, terms are defined as follows: "Connection" is not limited to mechanical connection, but can also include electrical connection. In other words, "connection" is not limited to direct connection between two elements to be connected, but can also include connection between two elements via another element interposed between them. "Containment" is not limited to containment of the entire component, but can also include containment of only a portion of the component (with the remaining portion of the component protruding). "Facing" means that the virtual projections of two objects overlap when viewed from a specific direction. In other words, "facing" is not limited to two objects directly facing each other, but can also include cases where two objects face each other with another component interposed between them. "Parallel," "orthogonal," and "same" can respectively include "substantially parallel," "substantially perpendicular," and "substantially the same."

In this disclosure, the +X direction, -X direction, +Y direction, -Y direction, +Z direction, and -Z direction are defined as follows: The +X direction is the direction from the first end 80e1 to the second end 80e2 of the metal plate 80 (described later) (see FIG. 8). The -X direction is the direction opposite to the +X direction. Hereinafter, when the +X direction and the -X direction are not distinguished, they will simply be referred to as the "X direction." The +Y direction and the -Y direction are directions that intersect (e.g., are perpendicular to) the X direction. The +Y direction is the direction from the third end 80e3 to the fourth end 80e4 of the metal plate 80 (described later) (see FIG. 8). The -Y direction is the direction opposite to the +Y direction. Hereinafter, when the +Y direction and the -Y direction are not distinguished, they will simply be referred to as the "Y direction." The +Z direction and the -Z direction are directions that intersect (e.g., are perpendicular to) the X direction and the Y direction. The +Z direction is the direction from the metal plate 80 (described below) toward the main body unit MU (see Figure 1). The -Z direction is the direction opposite to the +Z direction. Hereinafter, when there is no need to distinguish between the +Z direction and the -Z direction, they will simply be referred to as the "Z direction."

In the following, when there is no distinction between the X and Y directions, they may be referred to as the "horizontal direction." In the following, the Z direction may be referred to as the "vertical direction." In addition, in the following, the +Z direction side may be referred to as "up" and the -Z direction side may be referred to as "down." However, these expressions are used for convenience of explanation and do not limit the direction of gravity of the electrical connection unit 1 (the installation posture of the electrical connection unit 1).

(Embodiment)
<1. Configuration of the electrical connection unit>
FIG. 1 is a cross-sectional view showing an electrical connection unit 1 according to an embodiment. The electrical connection unit 1 is an in-vehicle device mounted on a vehicle such as an EV (Electric Vehicle), an HEV (Hybrid Electric Vehicle), or a PHEV (Plug-in Hybrid Electric Vehicle). The electrical connection unit 1 may also be referred to as an "electrical connection box" or a "junction box," for example. However, the electrical connection unit 1 is not limited to a box-shaped device.

The electrical connection unit 1 includes, for example, a main body MU, a metal plate (support member) 80, an insulating sheet 91 (see Figure 8), multiple first heat transfer members 92, and an insulating cover 93.

<2. Main body>
First, the main body unit MU will be described.
2 is a perspective view illustrating the main body unit MU. The main body unit MU is a part that performs the main function of the electrical connection unit 1 (for example, switching the electrical connection state or overcurrent protection). In this embodiment, the main body unit MU is divided into multiple subunits SU. The main body unit MU is formed by connecting multiple subunits SU. In this embodiment, the main body unit MU has three subunits SU (subunits SUX, SUY, and SUZ). Each subunit SU may be referred to as a "circuit assembly."

The subunit SUX has a first electrical function. The subunit SUX includes, for example, a plurality of electronic components 10X and a first wiring board (mounting member) 40X. The plurality of electronic components 10X are electrically connected to the first wiring board 40X.

The subunit SUY has a second electrical function. The second function is different from the first function. The subunit SUY includes, for example, multiple electronic components 10Y and a second wiring board (mounting member) 40Y. The multiple electronic components 10Y are electrically connected to the second wiring board 40Y.

The subunit SUZ has a third electrical function. The third function is different from the first and second functions. The subunit SUZ includes, for example, multiple electronic components 10Z and a third wiring board (mounting member) 40Z. The multiple electronic components 10Z are electrically connected to the third wiring board 40Z.

In this embodiment, the three subunits SUX, SUY, and SUZ are arranged side by side in the X direction. For example, subunit SUX is arranged on the +X direction side of subunit SUY. Subunits SUX and SUY are electrically connected via multiple connecting bus bars 75 that extend between the first routing board 40X and the second routing board 40Y. On the other hand, subunit SUZ is arranged on the -X direction side of subunit SUY. Subunits SUZ and SUY are electrically connected via multiple connecting bus bars 75 that extend between the third routing board 40Z and the second routing board 40Y. The connecting bus bars 75 are arranged on the opposite side of the multiple subunits SU from the metal plate 80.

In this embodiment, the three routing boards 40X, 40Y, and 40Z included in the three subunits SUX, SUY, and SUZ are arranged on the same plane. In other words, the three routing boards 40X, 40Y, and 40Z are arranged at the same height in the Z direction. As a result, the three routing boards 40X, 40Y, and 40Z form one large routing board 40M.

In this embodiment, the three subunits SUX, SUY, and SUZ have the same or similar basic structure. For this reason, the following detailed description will focus on one subunit SU. Below, when there is no need to distinguish between subunits SUX, SUY, and SUZ, they will simply be referred to as "subunits SU." Furthermore, when there is no need to distinguish between electronic component 10X, electronic component 10Y, and electronic component 10Z, they will simply be referred to as "electronic component 10." Furthermore, when there is no need to distinguish between first routing board 40X, second routing board 40Y, and third routing board 40Z, they will simply be referred to as "routing board 40."

In addition, instead of the above example, the main body unit MU does not have to be divided into multiple subunits SU. That is, the main body unit MU may be formed from multiple electronic components 10 and one wiring board 40. Furthermore, the two or more subunits SU are not limited to subunits SU with different functions, and may be subunits SU with the same function.

<3. Subunit Structure>
Next, the configuration of the subunit SU will be described.
Fig. 3 is a perspective view illustrating the subunit SU. Fig. 4 is a perspective view showing the subunit SU partially exploded. The subunit SU includes, for example, a plurality of electronic components 10, a plurality of connection components 20 for component connection, a plurality of connection components 30 for external connection, and a wiring board 40. The connection components 20, 30 are members that form a vertical current path. The connection components 20, 30 may also be referred to as "vertical wiring members."

<3.1 Electronic Components and Connecting Parts>
First, the electronic component 10 and the connecting component 20 for connecting the components will be described.
The electronic component 10 is an electronic component mounted on the subunit SU according to the functions required. The electronic component 10 may be, for example, a connector, a fuse, a relay (e.g., a mechanical relay or a semiconductor relay), a capacitor, a branching component, various sensors (e.g., a current sensor or a voltage sensor), an electronic control unit, or an electronic component unit formed by unitizing two or more of these. Note that the type of electronic component 10 is not limited to the above example. The electronic component 10 may be, for example, a heat-generating component that generates heat when power is applied. Below, a first type electronic component 10M and a second type electronic component 10N will be described as examples of the electronic component 10.

The connection component 20 is a component that electrically connects the electronic component 10 and the wiring board 40. The connection component 20 forms part of the electrical path in the subunit SU. The connection component 20 is made of metal (e.g., copper or a copper alloy). The connection component 20 may also be referred to as a "metal component." Below, a first type connection component 20M and a second type connection component 20N will be described as examples of the connection component 20.

3.1.1 First Type Electronic Component
The first type electronic component 10M is an electronic component in which a plurality of terminals 13 are arranged side by side at one end of the electronic component 10M. The electronic component 10M has, for example, a rectangular parallelepiped component main body 12, a plurality of terminals 13, and a plurality of mounting portions 14.

(Component body)
The component body 12 is a part that performs the main function of the electronic component 10M. For example, if the electronic component 10M is a relay, the component body 12 includes a switching part (e.g., a contact part) that switches between a conductive state and a non-conductive state. For example, if the electronic component 10M is a fuse, the component body 12 includes a fusing part that melts when an overcurrent flows. For example, if the electronic component 10M is a capacitor, the component body 12 includes a part that stores electric charge.

The component body 12 houses the components within an outer shell (case) that forms most of the exterior shape of the electronic component 10M. The case is made of, for example, synthetic resin and has insulating properties. The component body 12 has an insulating rib 11a that protrudes horizontally (for example, in the X direction) and extends in the Z direction. The insulating rib 11a is, for example, plate-shaped and extends horizontally (for example, in the X direction) and in the Z direction. The insulating rib 11a extends, for example, over the entire length of the component body 12 in the Z direction. The insulating rib 11a is arranged between multiple terminals 13 (terminals 13A and 13B, described below). The insulating rib 11a electrically insulates terminals 13A and 13B. In this embodiment, a portion of the insulating rib 11a is arranged between first portions 21 (described below) of two connecting parts 20M connected to the electronic component 10M. The insulating rib 11a electrically insulates the first portions 21 of the two connection parts 20M connected to the electronic component 10M.

(Terminal)
Terminals 13 are electrical connection portions exposed to the outside of component body 12. Terminals 13 are electrically connected to components inside the case. In this embodiment, electronic component 10M includes terminals 13A and 13B as the multiple terminals 13. One of terminals 13A and 13B is a positive terminal. The other of terminals 13A and 13B is a negative terminal.

In this embodiment, terminals 13A and 13B are provided at one end of electronic component 10M in the horizontal direction (e.g., the X direction). Terminals 13A and 13B are arranged side by side in the horizontal direction (e.g., the Y direction). Each terminal 13 has a mounting hole (not shown) into which a fastening member 71 (e.g., a screw or bolt) described below is attached. The mounting hole of each terminal 13 opens in the horizontal direction (e.g., the X direction). The inner surface of the mounting hole of each terminal 13 has a threaded groove.

(Mounting part)
The mounting portion 14 is a portion for fixing the electronic component 10M. The mounting portion 14 has mounting holes (unnumbered) to which fastening members 112 (e.g., screws or bolts, see FIG. 8 ), which will be described later, are attached. The mounting holes are open in the Z direction. The mounting holes are insertion holes through which the fastening members 112 are passed. The destinations to which the mounting portion 14 is fixed will be described later.

3.1.2 First type connecting part
The first-type connection component 20M is a component that electrically connects the first-type electronic component 10M to the routing board 40. In this embodiment, the connection component 20M electrically connects the electronic component 10M to a bus bar 42 (see FIG. 5 ) included in the routing board 40. The connection component 20M has, for example, a first portion 21 that rises above the routing board 40 and a second portion 22 that is disposed along the routing board 40.

(Part 1)
The first portion 21 of the connecting part 20M is a portion connected to the terminal 13 of the electronic component 10M. The first portion 21 is a plate-like or rectangular parallelepiped portion extending in the Z direction. The first portion 21 extends in the Z direction along one end (e.g., an end in the X direction) of the electronic component 10M. The first portion 21 is an upright portion that stands in the Z direction relative to the routing board 40 (e.g., relative to a bus bar 42 described below). The first portion 21 is adjacent to the electronic component 10M in the horizontal direction (e.g., the X direction). For example, the first portion 21 is adjacent to the terminal 13 of the electronic component 10M in the horizontal direction (e.g., the X direction) and is connected to the terminal 13 of the electronic component 10M from the horizontal direction (e.g., the X direction). The first part 21 of the connecting part 20M is physically and electrically connected to the terminal 13 of the electronic part 10M by inserting a fastening member 71 (e.g., a screw or bolt) into an attachment hole (not shown) and screwing and tightening this fastening member into the attachment hole of the terminal 13 of the electronic part 10M.

(Second part)
The second portion 22 of the connecting part 20M is a portion connected to the bus bar 42 (see FIG. 5). The second portion 22 protrudes horizontally (e.g., in the X direction) from the end of the first portion 21 on the −Z direction side. The second portion 22 is a plate portion extending horizontally. The second portion 22 is adjacent to (overlaps with) the bus bar 42 in the Z direction and is connected to the bus bar 42 from the Z direction. A fastening member 43 (e.g., a screw or bolt, see FIG. 5) protruding from the bus bar 42 in the +Z direction passes through the second portion 22. An engaging member 44 (e.g., a nut, see FIG. 3) is screwed and tightened onto the fastening member 43 that passes through the second portion 22, thereby physically and electrically connecting the second portion 22 to the bus bar 42.
In this embodiment, the first portion 21 and the second portion 22 form an L-shaped, single piece connecting part 20M.

3.1.3 Second type electronic components
The second type electronic component 10N is an electronic component in which two terminals 13 are arranged separately at both horizontal ends of the electronic component 10N. The electronic component 10N has, for example, a component main body 12 and a plurality of terminals 13. Note that, among the components of the electronic component 10N, components that have the same function as the electronic component 10M are assigned the same reference numerals. In this case, when describing the electronic component 10N, the "electronic component 10M" in the above description of the electronic component 10M can be read as the "electronic component 10N."

In electronic component 10N, terminals 13A and 13B are arranged separately at both ends of electronic component 10N in the horizontal direction (e.g., the X direction). Each terminal 13 has a mounting hole (not shown) into which a fastening member 72 (e.g., a screw or bolt) described below is attached. The mounting hole of each terminal 13 opens in the Z direction. For example, the mounting hole of each terminal 13 is an insertion hole through which the fastening member 72 is passed.

3.1.4 Second type connecting part
The second-type connection part 20N is a part that electrically connects the second-type electronic component 10N to the wiring board 40. In the present embodiment, the connection part 20N electrically connects the electronic component 10N to a bus bar 42 (see FIG. 5 ) included in the wiring board 40. The connection part 20N has, for example, a first portion 21, a second portion 22, and a third portion 23.

(Part 1)
The first portion 21 of the connection part 20N is connected to the terminal 13 of the electronic component 10N. The first portion 21 is a rectangular parallelepiped portion extending in the Z direction. The first portion 21 is an upright portion that stands in the Z direction relative to the routing board 40 (e.g., relative to the bus bar 42). The first portion 21 is adjacent to (overlaps with) the terminal 13 of the electronic component 10N in the Z direction and is connected to the terminal 13 of the electronic component 10N from the Z direction. The first portion 21 of the connection part 20N has a mounting hole (not shown) into which a fastening member 72 (e.g., a screw or bolt) described below is attached. The mounting hole of the connection part 20N opens upward and has a threaded groove on its inner circumferential surface. The terminal 13 of the electronic component 10N is physically and electrically connected to the terminal 13 of the electronic component 10N by passing the fastening member 72 through the mounting hole and screwing the fastening member into the mounting hole of the connection part 20N.

(Second part)
The second portion 22 of the connecting part 20N is a portion that is connected to the bus bar 42 (see FIG. 5). The second portion 22 protrudes in the horizontal direction (e.g., in the X direction) from the end of the first portion 21 on the −Z direction side. The second portion 22 is a plate portion that extends horizontally. The second portion 22 is adjacent to (overlaps with) the bus bar 42 in the Z direction and is connected to the bus bar 42 from the Z direction. The second portion 22 is physically and electrically connected to the bus bar 42 by passing a fastening member 43 (e.g., a screw or bolt, see FIG. 5) that protrudes from the bus bar 42 in the +Z direction through the second portion 22 and screwing and tightening an engaging member 44 (e.g., a nut, see FIG. 3) into the fastening member 43.

(Third part)
The third portion 23 is an upright wall (side wall) that stands in the +Z direction from both horizontal end portions of the second portion 22. The third portion 23 is a wall that extends along the Z direction. The third portion 23 is connected to the first portion 21 and also to the second portion 22. The third portion 23 extends at an incline that increases in the X direction as it progresses in the -Z direction, for example. The third portion 23 may be provided in the connection part 20M described above. On the other hand, the connection part 20N may not have the third portion 23.

3.2 External connection parts
Next, the connecting part 30 for external connection will be described.
The connection component 30 is a component that electrically connects the external connection bus bar 76 and the wiring board 40. In this embodiment, the connection component 30 electrically connects the external connection bus bar 76 and the bus bar 42 (see FIG. 5 ) included in the wiring board 40. The external connection bus bar 76 is electrically connected to an external device. In this disclosure, the term "external device" refers to an electrical device that exists outside the electrical connection unit 1. Examples of the external device include, but are not limited to, a battery unit mounted on a vehicle or an inverter for driving a vehicle motor. The connection component 30 has a configuration that includes, for example, a first portion, a second portion, and a third portion similar to the connection component 20M, and detailed description thereof will be omitted.

An external connection bus bar 76 is physically and electrically connected to the upper end of the connection component 30 (the upper end of the first portion) by a fastening member 73 (for example, a screw or a bolt).
The lower part (second part) of the connecting part 30 is physically and electrically connected to the bus bar 42 by passing a fastening member 43 (e.g., a screw or bolt, see Figure 5) protruding from the bus bar 42 in the +Z direction through the connecting part 30 and screwing and tightening an engaging member 44 (e.g., a nut, see Figure 3) onto the fastening member 43.

<3.3 Wiring board>
Next, the wiring board 40 will be described.
FIG. 5 is a perspective view showing a wiring board 40. The wiring board 40 is a component that forms at least a portion of the electrical paths between multiple electronic components 10 and/or at least a portion of the electrical paths between the electronic components 10 and an external device. In this disclosure, the term "wiring board" refers to a board-type wiring structure. "Board-type" refers to a plate-like structure that is flat when viewed overall, regardless of its detailed shape. In this disclosure, "plate-like,""sheet-like," or "flat" does not necessarily mean completely flat, but may also include cases where a fixing structure or rib protruding in the Z direction is present in some areas, or where an uneven surface conforming to the thickness of the bus bar is present on the surface. In this embodiment, the wiring board 40 is a plate-like structure that is flat along the X and Y directions.

The routing board 40 includes, for example, a base plate 41, one or more (e.g., multiple) bus bars 42, and multiple fastening members 43. In this embodiment, the base plate 41 and the multiple bus bars 42 are integrated by insert molding. For example, the routing board 40 is formed as a single piece by insert molding the bus bars 42 with the base plate 41 after the fastening members 43 are fixed to the bus bars 42. In other words, the bus bars 42 are integrated with the base plate 41 without using fastening members such as screws or bolts. The routing board 40 may be formed using a different structure instead of insert molding. For example, the routing board 40 may be molded separately from the bus bars 42, and an opening (corresponding to the receiving portion 55 described below) into which the bus bars 42 can be fitted may be formed in the routing board 40, and the bus bars 42 may be fixed in the opening to form a bus bar insert plate.

Figure 6 is a partially exploded perspective view of the wiring board 40. For ease of explanation, the base plate 41, bus bar 42, and fastening member 43 will be described below with reference to the partially exploded view of the wiring board 40.

(base plate)
The base plate 41 is a holding member that integrally holds together a plurality of bus bars 42 that are arranged horizontally at intervals from one another. The base plate 41 is made of, for example, synthetic resin and has insulating properties. The base plate 41 electrically insulates the plurality of bus bars 42 from one another. The base plate 41 is an example of a "base member" and an example of a "mounting member." The base plate 41 may also be referred to as an "insulating substrate." The base plate 41 has, for example, a flat portion 51 and a plurality of fixing portions 52.

The planar portion 51 is a plate-shaped portion of the base plate 41. The planar portion 51 is a plate-shaped portion that extends horizontally. The planar portion 51 forms the main portion of the base plate 41. The planar portion 51 forms the base (insulating base) of the base plate 41. In this embodiment, the planar portion 51 extends across the entire width of the base plate 41 in the X direction and across the entire width of the base plate 41 in the Y direction, excluding the four corners of the base plate 41.

The flat surface 51 has a first surface 51a and a second surface 51b. The first surface 51a is a surface facing the +Z direction. The first surface 51a is a flat surface extending horizontally. The first surface 51a faces the multiple electronic components 10 and also faces the insulating cover 93 (see Figure 1) of the electrical connection unit 1. The second surface 51b is located on the opposite side of the first surface 51a. The second surface 51b is a back surface facing the -Z direction. The second surface 51b is a flat surface extending horizontally. The second surface 51b faces the metal plate 80 (see Figure 1). The thickness direction of the flat surface 51 (plate thickness direction, normal direction to the first surface 51a and the second surface 51b) is the Z direction.

The planar portion 51 has, for example, one or more (e.g., multiple) accommodating portions 55 that each accommodate a bus bar 42. The multiple accommodating portions 55 are formed spaced apart from one another in the X or Y direction. Each accommodating portion 55 is, for example, a through-hole that penetrates the planar portion 51 in the Z direction. Note that instead of a through-hole, the accommodating portion 55 may be a recess provided on the first surface 51a or the second surface 51b of the planar portion 51 and recessed in the Z direction. Note that in this disclosure, the phrase "the accommodating portion penetrates the planar portion in the first direction (Z direction)" may also include cases where only a portion of the entire length of the accommodating portion 55 penetrates the planar portion 51 in the Z direction (for example, the remaining portion of the accommodating portion 55 may be a recess recessed in the Z direction, or may be provided inside the base plate 41 and not exposed to the outside of the base plate 41). Similarly, in this disclosure, "the storage section is recessed in the first direction (Z direction)" may also include the case where only a portion of the entire length of the storage section 55 is recessed in the Z direction (for example, the remaining portion of the storage section 55 may be a through-hole that penetrates the flat section 51 in the Z direction, or may be provided inside the base plate 41 and not exposed to the outside of the base plate 41).

When viewed from the Z direction, each accommodating section 55 has an outer shape corresponding to the shape of the bus bar 42 it accommodates. In this embodiment, the planar section 51 includes multiple accommodating sections 55, for example, five accommodating sections 55A, 55B, 55C, 55D, and 55E. Accommodating section 55A is provided to correspond to bus bar 42A (described below) and accommodates bus bar 42A. Accommodating section 55B is provided to correspond to bus bar 42B (described below) and accommodates bus bar 42B. Accommodating section 55C is provided to correspond to bus bar 42C (described below) and accommodates bus bar 42C. Accommodating section 55D is provided to correspond to bus bar 42D (described below) and accommodates bus bar 42D. Accommodating section 55E is provided to correspond to bus bar 42E (described below) and accommodates bus bar 42E.

(busbar)
The busbars 42 are routing members (electrical connection members) included in the routing board 40. The busbars 42 are, for example, routing members for electrically connecting multiple electronic components 10. Alternatively, the busbars 42 may be routing members for connecting the electronic components 10 to an external device. The busbars 42 are made of metal (for example, copper or a copper alloy) and are electrically conductive. In this embodiment, the routing board 40 includes, as the multiple busbars 42, five busbars 42A, 42B, 42C, 42D, and 42E. The five busbars 42A, 42B, 42C, 42D, and 42E are arranged horizontally at intervals from one another. The five busbars 42A, 42B, 42C, 42D, and 42E include portions that are arranged on the same plane. The five bus bars 42A, 42B, 42C, 42D, and 42E are held by a flat portion 51 of the base plate 41.

At least a portion of each bus bar 42 is plate-shaped and extends horizontally. At least a portion of each bus bar 42 is housed in the housing 55 and extends along the planar portion 51. That is, at least a portion of each bus bar 42 extends along the first surface 51a of the planar portion 51. At least a portion of each bus bar 42 extends horizontally within the housing 55. In this embodiment, each bus bar 42 is plate-shaped and extends horizontally throughout the entire length of the bus bar 42. Each bus bar 42 is housed in the housing 55 and extends along the planar portion 51 throughout its entire length (for example, over the first connection portion 61, second connection portion 62, extension portion 63, and extension portion 64, which will be described later). The upper and lower surfaces of each bus bar 42 can be flush with the upper and lower surfaces (first surface 51a and second surface 51b) of the planar portion 51. The upper surface of each bus bar 42 and the upper surface (first surface 51a) of the flat portion 51 form the component mounting surface of the wiring board 40. Hereinafter, the portion of each bus bar 42 that is housed in the housing portion 55 and extends along the flat portion 51 may be referred to as the "plate portion 42p." The bus bar 42 is a member that forms a horizontal current path. The bus bar 42 may also be referred to as a "horizontal wiring member."

Figure 7 is a plan view showing the wiring board 40. The plate portion 42p of each bus bar 42 has, for example, a first connection portion 61, a second connection portion 62, and an extension portion 63.

The first connection portion 61 is a portion that contacts one connection component 20 (hereinafter referred to as the "first connection component 20"). The first connection component 20 is a connection component that connects one electronic component 10 (hereinafter referred to as the "first electronic component 10") to the bus bar 42. The first connection portion 61 is a portion of the bus bar 42 that overlaps with the first connection component 20 when viewed from the Z direction. The first connection portion 61 is adjacent to the first connection component 20 in the Z direction and is connected to the first connection component 20 from the Z direction.

The second connection portion 62 is a portion that contacts another connection component 20 (hereinafter referred to as the "second connection component 20"). The second connection component 20 is a connection component that connects another electronic component 10 (hereinafter referred to as the "second electronic component 10") included in the plurality of electronic components 10 to the bus bar 42. The second connection portion 62 is a portion of the bus bar 42 that overlaps with the second connection component 20 when viewed from the Z direction. The second connection portion 62 is adjacent to the second connection component 20 in the Z direction and is connected to the second connection component 20 from the Z direction.

In addition, instead of the above example, the second connection portion 62 may be a portion that contacts another connection component 30 (hereinafter referred to as the "second connection component 30"). The connection component 30 is a connection component for connecting an external device to the bus bar 42. In this case, the second connection portion 62 is a portion of the bus bar 42 that overlaps with the second connection component 30 when viewed from the Z direction. The second connection portion 62 is adjacent to the second connection component 30 in the Z direction and is connected to the second connection component 30 from the Z direction.

In addition, the second connection portion 62 may be a portion that contacts the connecting bus bar 75 for connecting to another subunit SU, instead of the connecting parts 20, 30. In this case, the second connection portion 62 is a portion of the bus bar 42 that overlaps with the connecting bus bar 75 when viewed from the Z direction. The second connection portion 62 is adjacent to the connecting bus bar 75 in the Z direction and is connected to the connecting bus bar 75 from the Z direction.

The extension portion 63 extends in the X or Y direction from the first connection portion 61. The extension portion 63 is provided between the first connection portion 61 and the second connection portion 62. The extension portion 63 extends across the first connection portion 61 and the second connection portion 62. The extension portion 63 connects the first connection portion 61 and the second connection portion 62.

In this embodiment, the first connection portion 61, the second connection portion 62, and the extension portion 63 are plate-shaped and extend horizontally. In this embodiment, each bus bar 42 is housed in the housing portion 55 across at least the first connection portion 61 and the second connection portion 62, and extends along the flat portion 51. For example, the first connection portion 61, the second connection portion 62, and the extension portion 63 are housed in the housing portion 55 and extend along the flat portion 51.

In this embodiment, the extensions 63 of some bus bars 42 are accommodated in the accommodation section 55, and extend through the region R that overlaps with the electronic component 10 when viewed from the Z direction, spanning both sides of the region R. For example, the extensions 63 have a portion that extends linearly along the X direction. This portion extends through the region R that overlaps with the electronic component 10 when viewed from the Z direction, spanning both the +X and -X sides of the region R. In other words, by accommodating the bus bars 42 in the accommodation section 55, they can be routed more easily along a better route (e.g., a route with a shorter distance) without being obstructed by the presence of the electronic component 10.

The extension portion 63 of the busbar 42 may be formed in a crank shape, including a portion extending along the Y direction in addition to a portion extending along the X direction. The extension portion 63 may also have a portion extending at an angle relative to the X and Y directions. This allows the extension portion 63 to extend across the space between the first connection portion 61 and the second connection portion 62, which are offset in the Y direction.

The extension portion 63 extends from one of the first connection portion 61 and the second connection portion 62 so as to approach the other.
When two directions perpendicular to each other along the planar portion 51 of the base plate 41 are defined as a first direction (e.g., the X direction) and a second direction (e.g., the Y direction), the extension portion 63 is a portion that extends to one side in the first direction (the side approaching one of the two connection portions to the other) or one side in the second direction (the approaching side), and is a portion that extends diagonally to the two directions, including components of both one side in the first direction and one side in the second direction.
In the bus bar 42, the portion that extends beyond the first connection portion 61 and the second connection portion 62, or the portion that branches off and extends from the extension portion 63, and that overlaps with the electronic component 10 when viewed from the Z direction, is referred to as the extension portion 64 in this embodiment.

One or more bus bars 42 may also have an extension portion 64 in addition to the first connection portion 61, the second connection portion 62, and the extension portion 63. Here, the portion of the bus bar 42 consisting of the first connection portion 61, the second connection portion 62, and the extension portion 63 is referred to as the "connection path portion." The connection path portion electrically connects the first connection object and the second connection object. The "connection object" includes the electronic component 10 and the connection components 20 and 30. When the first connection portion 61 and the second connection portion 62 are connected to the electronic component 10, they are connected to the electronic component 10 via the connection component 20 adjacent to the component main body portion 12. In this embodiment, the extension portion 64 refers to a portion that extends from the first connection portion 61 and the second connection portion 62 outside the connection path portion and overlaps with the component main body portion 12 when viewed from the Z direction. The extension portion 64 is not limited to a portion that overlaps the electronic component 10 that is the connection object, but may also overlap a third electronic component 10 that is not the connection object. The extension portion 64 is not limited to extending from the connection portions 61 and 62, but may also extend from the extension portion 63.

The extension portion 64 is an extended or branched portion of the bus bar 42 for the purpose of expanding the heat dissipation area and/or increasing the heat capacity for heat storage (heat absorption). The extension portion 64 is not used for electrical connection. For example, the extension portion 64 is located on the opposite side of the first connection portion 61 (or the second connection portion 62) from the extension portion 63. The extension portion 64 is plate-shaped and extends horizontally. The extension portion 64 is housed in the housing portion 55 and extends along the flat portion 51. The extension portion 64 extends to the region R that overlaps with the electronic component 10 when viewed from the Z direction, and has the end 42e1 of the bus bar 42 at a position that overlaps with the electronic component 10 when viewed from the Z direction. In this embodiment, the extension portion 64 itself may overlap with the electronic component 10 and be used for heat storage/absorption.

Below, several examples of busbar 42 routing are described. The multiple electronic components 10 include three electronic components 10A, 10B, and 10C. Electronic components 10A and 10B are, for example, first-type electronic components 10M. Electronic component 10C is, for example, second-type electronic component 10N. The types of electronic components 10 are not limited to the above examples. The multiple connection components 20 include six connection components 20A, 20B, 20C, 20D, 20E, and 20F. The multiple connection components 30 include two connection components 30A and 30B. The multiple coupling bus bars 75 include two coupling bus bars 75A and 75B. The multiple external connection bus bars 76 include two external connection bus bars 76A and 76B.

(First wiring example)
First, an example of wiring for the bus bar 42A will be described. The bus bar 42A has a first connection portion 61, a second connection portion 62, and an extension portion 63. When viewed from the Z direction, the first connection portion 61 is located on the +X direction side of the electronic component 10A. The first connection portion 61 is electrically connected to a terminal 13A of the electronic component 10A via a connection component 20A, which is a first connection component 20. The second connection portion 62 is located on the −X direction side of the electronic component 10A when viewed from the Z direction. The second connection portion 62 is electrically connected to another subunit SU via a coupling bus bar 75A.

By being accommodated in the accommodation portion 55, the extension portion 63 passes through the region R that overlaps with the electronic component 10A when viewed from the Z direction, extending to both sides of the region R. For example, the extension portion 63 extends linearly along the X direction. The extension portion 63 extends through the region R that overlaps with the electronic component 10A when viewed from the Z direction, extending to both the +X and -X sides of the region R. The bus bar 42A is, for example, a bus bar included in the positive electrode line PL of the electrical connection unit 1.

(Second wiring example)
Next, an example of wiring of the bus bar 42B will be described. The bus bar 42B has a first connection portion 61, a second connection portion 62, an extension portion 63, and an extension portion 64. The first connection portion 61 is electrically connected to the terminal 13B of the electronic component 10A via the connection component 20B, which is the first connection component 20. The second connection portion 62 is electrically connected to the external connection bus bar 76A via the connection component 30A, which is the second connection component 30. The extension portion 64 extends to the region R that overlaps with the electronic component 10A when viewed from the Z direction, and has an end 42e1 of the bus bar 42 at a position that overlaps with the electronic component 10A. Note that, like the bus bar 42A, the bus bar 42B may have an extension portion 63 that passes through the region R that overlaps with the electronic component 10A when viewed from the Z direction and extends to both sides of the region R. The bus bar 42B is, for example, a bus bar included in the positive electrode line PL of the electrical connection unit 1.

(Third wiring example)
Next, an example of wiring of the bus bar 42C will be described. The bus bar 42C has a first connection portion 61, a second connection portion 62, an extension portion 63, and an extension portion 64. The first connection portion 61 is electrically connected to the terminal 13B of the electronic component 10B via the connection component 20C, which is the first connection component 20. The second connection portion 62 is electrically connected to another subunit SU via a coupling bus bar 75B. The extension portion 64 extends to the region R that overlaps with the electronic component 10B when viewed from the Z direction, and has an end 42e1 of the bus bar 42 at a position that overlaps with the electronic component 10B when viewed from the Z direction. The bus bar 42C is, for example, a bus bar included in the negative electrode line NL of the electrical connection unit 1.

(4th wiring example)
Next, an example of wiring of busbar 42D will be described. Busbar 42D has a first connection portion 61, a second connection portion 62, and an extension portion 63. First connection portion 61 is electrically connected to terminal 13A of electronic component 10B via connection part 20D, which is a first connection part 20. Second connection portion 62 is electrically connected to terminal 13B of electronic component 10C via connection part 20E, which is a second connection part 20. Busbar 42D is, for example, a busbar included in negative line NL of electrical connection unit 1.

(5th wiring example)
Next, an example of wiring of the bus bar 42E will be described. The bus bar 42E has a first connection portion 61, a second connection portion 62, and an extension portion 63. The first connection portion 61 is electrically connected to a terminal 13A of the electronic component 10C via a connection part 20F, which is a first connection part 20. The second connection portion 62 is electrically connected to an external connection bus bar 76B via a connection part 30B, which is a second connection part 30. The bus bar 42E is, for example, a bus bar included in the negative line NL of the electrical connection unit 1.

(Fastening member)
6 , the fastening member 43 will be described. The fastening member 43 is a component for fastening the bus bar 42 to a component to be connected to the bus bar 42 (connection component 20, connection component 30, or coupling bus bar 75). The fastening member 43 is, for example, a crimp bolt fixed to the bus bar 42.

In this embodiment, each of the first connection portion 61 and the second connection portion 62 of the bus bar 42 has a through hole 42h. The through hole 42h penetrates the bus bar 42 in the Z direction. The fastening member 43 is, for example, a bolt having a shaft portion 43a and a head portion 43b. The circumferential surface of the shaft portion 43a has a threaded groove. The head portion 43b has a larger diameter than the shaft portion 43a. The fastening member 43 is fixed to the bus bar 42 by crimping, with the shaft portion 43a passing through the through hole 42h of the bus bar 42. With this fixation, the fastening member 43 is electrically and physically connected to the bus bar 42, with the shaft portion 43a protruding from the through hole 42h of the bus bar 42 in the +Z direction. Note that the fastening member 43 is not limited to being fixed by crimping, and may also be fixed to the bus bar 42 by welding or other methods.

In this embodiment, the connecting component 20 is first fixed to the electronic component 10 by the fastening member 71 or the fastening member 72, and then attached to the fastening member 43 from the Z direction. For example, the shaft 43a of the fastening member 43 is inserted into the second mounting hole (through hole) 22h of the second portion 22 of the connecting component 20. Then, an engaging member 44 (e.g., a nut) is engaged with the shaft 43a of the fastening member 43 protruding from the second mounting hole 22h of the second portion 22 of the connecting component 20. The engaging member 44 is attached to the shaft 43a, for example, along the Z direction. This engagement secures the second portion 22 of the connecting component 20 to the fastening member 43.

4. Metal Plate, Insulating Sheet, First Heat Transfer Member, and Insulating Cover
Next, the metal plate 80, the insulating sheet 91, the first heat transfer member 92, and the insulating cover 93 will be described.

<4.1 Metal Plate>
8 is a partially exploded perspective view of the electrical connection unit 1. The metal plate 80 is a member that ensures the rigidity of the electrical connection unit 1 and enhances the heat dissipation of the electrical connection unit 1. The metal plate 80 is made of metal (for example, aluminum or an aluminum alloy). The metal plate 80 may also be referred to as a "rigid member."

When viewed from the Z direction, the metal plate 80 has a rectangular shape aligned with the X direction. The metal plate 80 has a first end 80e1, a second end 80e2, a third end 80e3, and a fourth end 80e4. The first end 80e1 and the second end 80e2 are a pair of ends in the longitudinal direction of the metal plate 80 and are spaced apart in the X direction. The third end 80e3 and the fourth end 80e4 are a pair of ends in the lateral direction of the metal plate 80 and are spaced apart in the Y direction. The metal plate 80 includes, for example, a flat portion 81, multiple fixing portions 82, and multiple fixing portions 83.

The flat surface portion 81 is a plate-shaped portion of the metal plate 80. The flat surface portion 81 is a plate-shaped portion that extends horizontally. The flat surface portion 81 forms the main portion of the metal plate 80. The flat surface portion 81 forms the base (metal base) of the metal plate 80. In this embodiment, the flat surface portion 81 is large enough to cover the three subunits SU from below. The flat surface portion 81 faces the wiring board 40 of the three subunits SU. In this embodiment, the metal plate 80 faces the second surface 51b of the flat surface portion 51 of each subunit SU, with a gap S1 (see Figure 10) between it and the second surface 51b of the flat surface portion 51 of each subunit SU.

The fixing portion 82 is a fixing portion for fixing the base plate 41 of each subunit SU to the metal plate 80. When viewed from the Z direction, the fixing portion 82 is provided at a position corresponding to the fixing portion 52 of the base plate 41 of each subunit SU. The fixing portion 82 is a cylindrical or prismatic boss that protrudes in the +Z direction from the flat portion 81 of the metal plate 80.

The fixing portion 83 is a fixing portion for fixing the electronic component 10 of each subunit SU directly to the metal plate 80 without using the base plate 41. When viewed from the Z direction, the fixing portion 83 is provided at a position corresponding to the mounting portion 14 of the electronic component 10 of each subunit SU. The fixing portion 83 is a cylindrical or prismatic boss that protrudes from the flat portion 81 in the +Z direction.

<4.2 Insulation sheet>
The insulating sheet 91 is an insulating member for electrically insulating the metal plate 80 from the bus bars 42 of each subunit SU. The insulating sheet 91 is made of a synthetic resin such as polyester or polyimide, and has insulating properties. The insulating sheet 91 has a rectangular shape when viewed from the Z direction. The insulating sheet 91 has a sheet shape that extends horizontally. The insulating sheet 91 is disposed between the flat surface 81 of the metal plate 80 and the wiring board 40 of each subunit SU. For example, the insulating sheet 91 is disposed between the flat surface 81 of the metal plate 80 and a plurality of first heat transfer members 92.

In this embodiment, the insulating sheet 91 is attached to the flat portion 81 of the metal plate 80. The insulating sheet 91 has cutouts or openings to avoid the fixing portions 82 and 83 of the metal plate 80. Note that, instead of the above example, the insulating sheet 91 may be provided between the wiring board 40 of each subunit SU and the multiple first heat transfer members 92. Note that if the first heat transfer members 92 have insulating properties and the necessary insulation is ensured by the first heat transfer members 92, the insulating sheet 91 may be omitted.

4.3 First heat transfer member
The first heat transfer member 92 is a member for transferring heat generated by the electronic component 10 when current is applied and/or heat (Joule heat) generated by the bus bar 42 itself when current is applied to the metal plate 80. The first heat transfer member 92 is, for example, an elastic heat transfer sheet (for example, a thermally conductive silicone sheet). However, the first heat transfer member 92 is not limited to the above example and may be a heat transfer member formed of a thermally conductive gel or other materials.

Figure 9 is a bottom view showing the routing board 40. In this embodiment, the multiple first heat transfer members 92 are partially provided on the routing board 40. For example, the multiple first heat transfer members 92 are arranged in positions that overlap with portions of the bus bars 42 when viewed from the Z direction. Furthermore, the multiple first heat transfer members 92 are arranged in positions that overlap with portions of the bus bars 42 near the electronic components 10 (e.g., electronic components 10A and 10B) when viewed from the Z direction. In this embodiment, the multiple first heat transfer members 92 are arranged in positions that overlap with the connecting components 20 when viewed from the Z direction.

Figure 10 is a cross-sectional view of the structure shown in Figure 7 taken along line A-A. In this embodiment, the first heat transfer member 92 is disposed between the metal plate 80 and the bus bar 42. The first heat transfer member 92 transfers heat transferred from the electronic component 10 to the bus bar 42 and/or heat generated in the bus bar 42 from the bus bar 42 to the metal plate 80.

In this embodiment, a portion of the first heat transfer member 92 contacts the bus bar 42 at a position that overlaps the connection component 20 when viewed from the Z direction. In this case, the first heat transfer member 92 makes it easier to transfer heat that is transferred from the terminal 13 of the electronic component 10 to the connection component 20 from the connection component 20 to the metal plate 80 via the bus bar 42.

In addition, in this embodiment, a portion of the first heat transfer member 92 is positioned so as to overlap the head 43b of the fastening member 43 when viewed from the Z direction, and is in contact with the head 43b of the fastening member 43. In this case, the first heat transfer member 92 makes it easier to transfer heat transferred from the terminal 13 of the electronic component 10 to the connecting part 20 from the fastening member 43 to the metal plate 80.

In addition, in this embodiment, a portion of the first heat transfer member 92 contacts the bus bar 42 at a position that overlaps the electronic component 10 when viewed from the Z direction. In this case, the first heat transfer member 92 makes it easier to transfer heat transferred from the electronic component 10 to the bus bar 42 from the bus bar 42 to the metal plate 80. In the example shown in FIG. 10 , the upper surface of the bus bar 42 contacts the electronic component 10, thereby thermally connecting the bus bar 42 to the electronic component 10. Note that the portion of the bus bar 42 that is thermally connected to the electronic component 10 may be the extension portion 63 or the extension portion 64.

(Modification)
11 is a cross-sectional view showing one modified example. In this modified example, an air layer AS, which is a gap, exists between the bus bar 42 and the electronic component 10. The bus bar 42 is thermally connected to the electronic component 10 via the air layer AS. With this configuration, heat generated by the electronic component 10 transfers to the bus bar 42 through the air layer AS. The heat transferred to the bus bar 42 is transferred to the metal plate 80 via the first heat transfer member 92 and dissipated there.

(Modification)
FIG. 12 is a cross-sectional view showing another modified example. In this modified example, a second heat transfer member 98 is provided between the bus bar 42 and the electronic component 10. The second heat transfer member 98 is interposed between the bus bar 42 and the electronic component 10 in the Z direction. The bus bar 42 is thermally connected to the electronic component 10 via the second heat transfer member 98. The second heat transfer member 98 transfers heat generated by the electronic component 10 to the bus bar 42. The second heat transfer member 98 is, for example, an elastic heat transfer sheet (e.g., a thermally conductive silicone sheet). However, the second heat transfer member 98 is not limited to the above example and may be a heat transfer member formed of a thermally conductive gel or other material. With this configuration, heat generated by the electronic component 10 is efficiently transferred to the bus bar 42 via the second heat transfer member 98. The heat transferred to the bus bar 42 is transferred to the metal plate 80 via the first heat transfer member 92 and dissipated there.

<4.4 Insulating cover>
Returning to FIG. 1 , the insulating cover 93 will be described. The insulating cover 93 is a member for preventing fingers from touching the electrical paths of the main body unit MU. The insulating cover 93 is made of, for example, synthetic resin and has insulating properties. The insulating cover 93 is, for example, box-shaped with an open side in the -Z direction. The insulating cover 93 has multiple air vents 93h. The insulating cover 93 is attached to the metal plate 80 along the Z direction. Note that the insulating cover 93 is not limited to a box-shaped member, and may be a sheet-shaped member that covers the electrical paths of the main body unit MU.

<5. Exposed busbar structure>
Next, the exposed structure of the bus bar 42 will be described.

<5.1 Exposed structure of the upper surface of the busbar>
First, referring to Fig. 5, the exposed structure on the upper surface side of the bus bar 42 will be described. In this embodiment, at least a portion of the extension portion 63 of the bus bar 42 is exposed on the upper surface side (the first surface 51a side of the flat portion 51) to the outside of the base plate 41. For example, the extension portion 63 of the bus bar 42 is exposed on the upper surface side to the outside of the base plate 41 in at least a portion of the region R (see Fig. 7) that overlaps with the electronic component 10 when viewed from the Z direction.

In this embodiment, the bus bar 42 is housed in the housing 55 over at least the entire length between the first connection portion 61 and the second connection portion 62 and extends along the first surface 51a of the flat portion 51. The bus bar 42 is exposed to the outside of the base plate 41 on the upper surface side over at least the entire length between the first connection portion 61 and the second connection portion 62.

In this embodiment, the bus bar 42 is housed in the housing portion 55 over its entire length and extends along the first surface 51a of the planar portion 51. The bus bar 42 is exposed to the outside of the base plate 41 on the upper surface side over its entire length.

As shown in FIG. 10 , at least a portion of the extension 63 of the bus bar 42 is exposed outside the base plate 41 on the lower surface (second surface 51b side) as well as the upper surface. For example, the bus bar 42 is exposed outside the base plate 41 on the lower surface side along the entire length of the bus bar 42.

<5.2 Exposed structure of the underside of the busbar>
Next, the exposed structure of the lower surface side of the bus bar 42 will be described with reference to Fig. 10. In this embodiment, the plate portion 42p of the bus bar 42 includes an exposed portion 42u on the lower surface side (the second surface 51b side of the flat portion 51) that is exposed to the outside of the base plate 41. In this embodiment, the exposed portion 42u of the bus bar 42 extends over the entire length of the bus bar 42. In this embodiment, the first heat transfer member 92 is disposed between the exposed portion 42u of the bus bar 42 and the metal plate 80. For example, the first heat transfer member 92 contacts the exposed portion 42u of the bus bar 42.

In this embodiment, at least a portion of the exposed portion 42u of the bus bar 42 is provided in a region that overlaps with the connection part 20 when viewed from the Z direction. At least a portion of the first heat transfer member 92 overlaps with the exposed portion 42u of the bus bar 42 in a region that overlaps with the connection part 20 when viewed from the Z direction. For example, at least a portion of the first heat transfer member 92 contacts the exposed portion 42u of the bus bar 42 in a region that overlaps with the connection part 20 when viewed from the Z direction.

In this embodiment, the exposed portion 42u of the busbar 42 includes a first portion 42ua arranged in an area overlapping the connecting component 20 when viewed from the Z direction, and a second portion 42ub arranged in an area overlapping the electronic component 10 when viewed from the Z direction.

The first heat transfer member 92 includes a first heat transfer portion 92a and a second heat transfer portion 92b. The first heat transfer portion 92a overlaps with the first portion 42ua of the exposed portion 42u of the busbar 42 in a region that overlaps with the connecting part 20 when viewed from the Z direction. For example, the first heat transfer portion 92a contacts the first portion 42ua of the exposed portion 42u of the busbar 42. On the other hand, the second heat transfer portion 92b overlaps with the second portion 42ub of the exposed portion 42u of the busbar 42 in a region that overlaps with the electronic component 10 when viewed from the Z direction. For example, the second heat transfer portion 92b contacts the second portion 42ub of the exposed portion 42u of the busbar 42.

As described above, at least a portion of the extension 63 of the busbar 42 is exposed to the outside of the base plate 41 on the upper surface (first surface 51a side) as well as the lower surface. For example, the busbar 42 is exposed to the outside of the base plate 41 on the upper surface side over the entire length of the busbar 42. For example, the second portion 42ub of the exposed portion 42u of the busbar 42 is exposed to the outside of the base plate 41 on the upper surface side as well as the lower surface side, and faces the electronic component 10.

14. Advantages of this embodiment
<A. Advantages of wiring boards>
As a comparative example, consider an electrical connection unit in which the bus bars are arranged in an upright position relative to the bottom wall of the housing. In this comparative example, the width of the upright bus bars may make it difficult to reduce the height of the electrical connection unit.

In contrast, in this embodiment, the electrical connection unit 1 has a first electronic component 10 and a routing board 40. The routing board 40 includes a base plate 41 and a first bus bar 42. The base plate 41 has a plate-shaped flat portion 51 with a first surface 51a facing the first electronic component 10. The flat portion 51 has a first accommodating portion 55 that is recessed in the Z direction or that penetrates the flat portion 51 in the Z direction. At least a portion of the first bus bar 42 is accommodated in the first accommodating portion 55 and extends along the flat portion 51. With this configuration, compared to the structure of the comparative example described above, in which at least a portion of the routing path is formed on a flat surface, the bus bar is less likely to affect the height direction, making it easier to reduce the height of the electrical connection unit 1.

In this embodiment, the electrical connection unit 1 has a first connection component 20. The first connection component 20 includes a portion that stands upright relative to the first bus bar 42, and electrically connects the first electronic component 10 and the first bus bar 42. The first bus bar 42 has a first connection portion 61 that contacts the first connection component 20. The first connection portion 61 is housed in the first housing portion 55 and extends along the planar portion 51. With this configuration, a larger portion of the wiring path is formed on a flat surface, further facilitating a low-profile electrical connection unit 1.

In this embodiment, the electrical connection unit 1 has a second connection component 20. The second connection component 20 includes a portion that stands upright relative to the first bus bar 42 and electrically connects the first bus bar 42 to a second electronic component or external equipment. The first bus bar 42 has a second connection portion 62 that contacts the second connection component 20. The first bus bar 42 is housed in the first housing portion 55 across at least the first connection portion 61 and the second connection portion 62 and extends along the flat portion 51. With this configuration, a larger portion of the wiring path is formed on a flat surface, further facilitating a low-profile electrical connection unit 1.

In this embodiment, the first bus bar 42 has an extension portion 63 between the first connection portion 61 and the second connection portion 62. The extension portion 63 is housed in the first housing portion 55 and extends through the region R that overlaps with the electronic component 10 when viewed from the Z direction, spanning both sides of the region R. With this configuration, housing the extension portion 63 in the first housing portion 55 reduces the constraints on the wiring layout due to the presence of the electronic component 10. This enables a wiring layout that provides more advantageous electrical characteristics, such as making it easier to extend the extension portion 63 in a straight line. Furthermore, routing the bus bar in a way that bypasses the electronic component 10 can be avoided. This improves the electrical characteristics of the electrical connection unit 1 and/or reduces the size of the electrical connection unit 1.

In this embodiment, the first bus bar 42 has an extension 64 that extends to the region R that overlaps with the first electronic component 10 when viewed from the Z direction, and has an end 42e1 at a position that overlaps with the first electronic component 10. The extension 64 is housed in the first housing 55 and extends along the planar portion 51. With this configuration, housing the extension 64 in the first housing 55 reduces the height of the electrical connection unit 1, while allowing a metallic heat dissipation portion (extension 64) to be positioned below the first electronic component 10 to promote heat dissipation and/or heat storage of the first electronic component 10. This improves the heat dissipation and/or heat storage properties of the electrical connection unit 1.

In this embodiment, the first bus bar 42 is housed in the first housing portion 55 over its entire length and extends along the flat portion 51. With this configuration, a larger portion of the wiring path is formed on a flat surface, making it even easier to reduce the height of the electrical connection unit 1.

In this embodiment, the electrical connection unit 1 has a second bus bar 42 electrically connected to the second terminal 13B of the first electronic component 10. The flat portion 51 has a second accommodating portion 55 that is recessed in the Z direction or that penetrates the flat portion 51 in the Z direction, located at a position away from the first accommodating portion 55. At least a portion of the second bus bar 42 is accommodated in the second accommodating portion 55 and extends along the flat portion 51. With this configuration, a larger portion of the wiring path including multiple bus bars 42 is held flat by a single base plate 41, further facilitating the reduction in height of the electrical connection unit 1.

In this embodiment, the electrical connection unit 1 has a third bus bar 42. The first bus bar 42 is a bus bar included in the positive electrode line PL. The third bus bar 42 is a bus bar included in the negative electrode line NL. The flat portion 51 has a third housing portion 55 that is recessed in the Z direction or penetrates the flat portion 51 in the Z direction, at a position away from the first housing portion 55. At least a portion of the third bus bar 42 is housed in the third housing portion 55 and extends along the flat portion 51. With this configuration, a larger portion of the wiring paths forming the positive electrode line PL and the negative electrode line NL are held flat by a single base plate 41, further facilitating a low-profile electrical connection unit 1.

In this embodiment, the electrical connection unit 1 includes a fourth bus bar 42, a fifth bus bar 42, and a third connection component 100 that electrically connects the fourth bus bar 42 and the fifth bus bar 42. The planar portion 51 has a fourth housing portion 55 that is recessed in the Z direction or penetrates the planar portion 51 in the Z direction, located at a position away from the first housing portion 55. At least a portion of the fourth bus bar 42 is housed in the fourth housing portion 55 and extends along the planar portion 51. The third connection component 100 includes a portion that stands upright relative to the fourth bus bar 42. The fifth bus bar 42 is supported by the third connection component 100 at a position away from the first bus bar 42 in the Z direction and extends parallel to the first surface 51a. This configuration facilitates the formation of a three-dimensional wiring path using the fourth bus bar 42, the third connection component 100, and the fifth bus bar 42. This allows for the provision of an electrical connection unit 1 with excellent assembly properties. Furthermore, by placing the fourth bus bar 42 in the housing portion 55 of the base plate 41, part of the three-dimensional wiring path is formed within the thickness of the base plate 41. This makes it even easier to reduce the height of the electrical connection unit 1.

In this embodiment, the fifth bus bar 42 extends across the first bus bar 42 at a position spaced apart from the first bus bar 42 in the Z direction. This configuration makes it easy to form a wiring path that crosses the first bus bar 42 over a three-dimensional space using the third connection component 100 and the fifth bus bar 42. This makes it possible to provide an electrical connection unit 1 that is easy to assemble.

<B. Advantages of Flat Busbars>
As a comparative example, consider an electrical connection unit in which the bus bars are arranged in an upright position relative to the bottom wall of the housing. In this comparative example, the bus bars must be fixed to the housing in an upright position, making it difficult to improve the workability of attaching the bus bars. In this case, it may be difficult to improve the ease of assembly of the electrical connection unit 1.

In contrast, in this embodiment, the electrical connection unit 1 has a base plate 41 and a bus bar 42. The base plate 41 includes a plate-shaped flat portion 51. The flat portion 51 has a first housing portion 55 that is recessed in the Z direction or that penetrates the flat portion 51 in the Z direction. At least a portion of the bus bar 42 is housed in the first housing portion 55 and extends along the flat portion 51. This configuration makes it easier to handle the base plate 41 and bus bar 42 as a single unit, improving the workability of installing the bus bar compared to the configuration of the comparative example described above. This improves the ease of assembly of the electrical connection unit 1.

In this embodiment, the bus bar 42 is housed in the housing portion 55 over the entire length of the bus bar 42 and extends along the flat portion 51. This configuration improves the assembly ease of the electrical connection unit 1 while also making it easier to reduce the height of the electrical connection unit 1.

In this embodiment, the bus bar 42 is integrated with the base plate 41 by insert molding. This configuration eliminates or reduces the need for manual attachment of the bus bar 42 to the housing. This further improves the ease of assembly of the electrical connection unit 1.

This embodiment includes a fastening member 43 that protrudes from the bus bar 42 in the Z direction, and connection components 20, 30 that are attached to the fastening member 43 from the Z direction. The connection components 20, 30 electrically connect the electronic component 10 or external equipment to the bus bar 42. This configuration makes it easier to align the direction of the work required to attach the component to the bus bar 42 with the Z direction. Aligning the work direction further improves the ease of assembly of the electrical connection unit 1.

In this embodiment, the connection component 20 is connected to the electronic component 10 from the X direction (or Y direction). With this configuration, for electronic components 10 that need to be connected from the X direction, the connection direction of the electronic component 10 relative to the bus bar 42 can be changed to the Z direction by using the connection component 20. This further improves the ease of assembly of the electrical connection unit 1.

<C. Advantages of the exposed structure on the top side of the busbar>
As a comparative example, consider an electrical connection unit in which the upper surface of the bus bar 42 is covered with synthetic resin. With the configuration of this comparative example, it is difficult to improve the heat dissipation performance of the bus bar 42.

In this embodiment, the electrical connection unit 1 includes a first electronic component 10 and a routing board 40. The routing board 40 includes a base plate 41 and a bus bar 42. The base plate 41 has a plate-shaped flat portion 51 having a first surface 51a facing the first electronic component 10 and a second surface 51b located on the opposite side of the first surface 51a. The flat portion 51 has a housing portion 55 that is recessed in the Z direction or that penetrates the flat portion 51 in the Z direction. At least a portion of the bus bar 42 has a plate portion 42p that is housed in the housing portion 55 and extends along the flat portion 51. The plate portion 42p includes a first connection portion 61 that overlaps with the first connection component 20 when viewed in the Z first direction, and an extension portion 63 that extends from the first connection portion 61 in a direction intersecting the Z direction. At least a portion of the extension 63 is exposed to the outside of the base plate 41 on the first surface 51a side. With this configuration, at least a portion of the bus bar 42 other than the connection portions 61, 62 that connect to other components is exposed to the outside and functions as an area for dissipating heat. In this case, the heat dissipation performance of the electrical connection unit 1 can be improved.

In this embodiment, the extension portion 63 is exposed to the outside of the base plate 41 on the first surface 51a side in at least a portion of the region R that overlaps with the first connection component 20 when viewed from the Z direction. This configuration makes it easier for a portion of the extension portion 63 to function as a heat dissipation portion that transfers heat from the first connection component 20. In this case, the heat dissipation performance of the electrical connection unit 1 can be improved.

In this embodiment, the first bus bar 42 has a second connection portion 62 that overlaps with the second connection components 20, 30 when viewed in the Z direction. The first bus bar 42 is housed in the housing portion 55 and extends along the flat portion 51 over at least the entire length between the first connection portion 61 and the second connection portion 62, and is exposed to the outside of the base plate 41 on the first surface 51a side. With this configuration, a wider portion functions as a heat dissipation area, further improving the heat dissipation performance of the electrical connection unit 1.

In this embodiment, the bus bar 42 is housed in the housing portion 55 over its entire length, extending along the flat portion 51 and exposed to the outside of the base plate 41 on the first surface 51a side. With this configuration, a wider portion functions as a heat dissipation area, further improving the heat dissipation performance of the electrical connection unit 1.

At least a portion of the extension 63 is exposed to the outside of the base plate 41 on both the first surface 51a and the second surface 51b. With this configuration, a larger portion functions as a heat dissipation area, further improving the heat dissipation performance of the electrical connection unit 1.

In a modified example of this embodiment, the electrical connection unit 1 has a metal plate 80 facing the flat portion 51 with a gap S1 between it and the flat portion 51, and a first heat transfer member 92 arranged between the bus bar 42 and the metal plate 80. The base plate 41 has a cover portion 51v that covers at least a portion of the extension portion 63 on the second surface 51b side. With this configuration, even if heat tends to be trapped in the gap S1 between the base plate 41 and the metal plate 80, the provision of the cover portion 51v can prevent heat from being trapped in the gap S1.

<D. Advantages of the exposed structure on the underside of the busbar>
To improve the retention of the busbar 42, a structure may be adopted in which the busbar 42 is covered with resin except for the surface where it is connected to the electronic components 10, etc. However, a structure that covers the busbar 42 except for the surface where it is connected has the problem of poor heat dissipation from the busbar 42. In this embodiment, the underside of the busbar 42 (the surface opposite the component mounting surface) is exposed, and a heat transfer sheet is attached to this exposed surface. The heat transfer sheet is connected to a metal plate 80 (rigid member, heat dissipation member) provided below the wiring board 40. This allows for good heat transfer from the busbar 42 to the metal plate 80 (the side opposite the component mounting surface) via the heat transfer sheet.

E. Advantages of Busbar Extensions
In this embodiment, the wiring board 40 includes a board body having a bus bar 42 integrally held therein (including by insertion and fitting), and an electronic component 10 mounted on the wiring board 40. The bus bar 42 includes a connection path portion (a first connection portion 61, a second connection portion 62, and an extension portion 63) extending between a first connection object (the electronic component 10 or the connecting component 20, 30) and a second connection object (another electronic component 10 or another connecting component 20, 30), and an extension portion (excess length portion) 64 extending outward from the connection path portion and overlapping with the component body portion (heat-generating portion) 12 of the electronic component 10 when viewed from the normal direction (Z direction) of the wiring board 40.
According to this configuration, the bus bar 42 held on the wiring board 40 has an extension 64 that extends outward from the connection path portion, and this extension 64 overlaps with the component body 12 of the electronic component 10, so that heat generated by the electronic component 10 can be transferred to the bus bar 42 via the extension 64. This makes it possible to use the bus bar 42 as a heat storage member, thereby improving the heat storage capacity of the electrical connection unit 1.

In this embodiment, the bus bar 42 is integrated with the wiring board 40 by insert molding.
With this configuration, by inserting the bus bars 42 into the wiring board 40, the component mounting surface of the wiring board 40 can be made flush, thereby reducing the thickness of the wiring board 40. The bus bars 42 can be easily exposed on both sides of the board, and heat from the electronic components 10 can be easily dissipated to the back side of the wiring board 40 through the bus bars 42.

In this embodiment, the extension 64 comes into contact with the component body 12 of the electronic component 10 via the second heat transfer member 98 .
With this configuration, the extension portion 64 comes into contact with the electronic component 10 via the second heat transfer member 98, thereby improving heat transfer from the electronic component 10 to the extension portion 64 and further improving the heat storage capacity of the electrical connection unit 1.

<Modification>
Next, several modified examples will be described. Note that the configuration of each modified example other than that described below is the same as that of the above-described embodiment.

(First Modification)
The wiring board 40 is not limited to a structure in which the base plate 41 and the bus bar 42 are integrated by insert molding. For example, the base plate 41 having the accommodation portion 55 for accommodating the bus bar 42 may be molded, and then the bus bar 42 may be placed in the accommodation portion 55. In this case, the bus bar 42 may be fixed to the accommodation portion 55 by fitting, or may be fixed to the accommodation portion 55 by adhesive or other fixing means. In these cases, potting may be applied to fill the gap between the bus bar 42 and the accommodation portion 55.

(Second Modification)
The base member of the routing substrate 40 is not limited to the base plate 41 having the plate-shaped flat portion 51. The routing substrate 40 may be a base member (e.g., an insulating sheet) having a sheet-shaped flat portion 51. In this case, the accommodation portion 55 may be formed by a portion of the flat portion 51 conforming to the outer shape of the bus bar 42. In the present disclosure, the term "sheet-shaped" or "sheet" is not limited to a member having a thickness of 1 mm or more, and may also refer to a member having a thickness of less than 1 mm (so-called film).

(Third Modification)
The base plate 41 of the wiring board 40 may include multiple members (plate members or sheet members). The multiple members are arranged to sandwich the multiple bus bars 42 arranged horizontally, for example, from both sides in the Z direction. For example, the multiple members are integrated by sandwiching the multiple bus bars 42, for example, by lamination molding. The multiple members form a planar portion 51. In this case, the accommodation portion 55 may be formed hollow inside the base plate 41 (between the multiple members). The multiple members may be multiple plate members, multiple sheet members, or a combination of plate members and sheet members. The sheet member may be, for example, a flexible sheet member. The planar portion 51 formed by the multiple members has an opening that exposes at least the first connection portion 61 and the second connection portion 62 of the bus bars 42. For example, in this case, the accommodation portion 55 formed between the multiple members corresponds to an example of an "accommodation portion recessed in the first direction (Z direction)."

(Fourth Modification)
The connection between the electronic component 10 and the bus bar 42 is not limited to the connection via the connection component 20. The electronic component 10 may be directly connected to the bus bar 42 using a fastening member (e.g., a bolt or a screw), welding, or the like.

A number of embodiments and variations have been described above. However, the embodiments and variations are not limited to the examples described above. For example, multiple embodiments may be realized in combination with each other.

REFERENCE SIGNS LIST 1 Electrical connection unit 10 Electronic component 12 Component main body 20, 30 Connection component 40 Wiring board 41 Base plate 42 Bus bar 51 Planar portion 51a First surface 51b Second surface 61 First connection portion 62 Second connection portion 63 Extension portion 64 Extension portion 80 Metal plate 92 First heat transfer member 98 Second heat transfer member

Claims (5)

a first connection object which is either a first electronic component, a connection component connected to the first electronic component, or a connection component for external connection;
a second connection object which is either a second electronic component, a connection component connected to the second electronic component, or a connection component for external connection;
a base member having a plate-like or sheet-like planar portion facing the first connection object and the second connection object;
a bus bar held on the planar portion and electrically connecting the first connection object and the second connection object;
Equipped with
When a thickness direction of the planar portion is defined as a first direction, the planar portion has a housing portion that is recessed in the first direction or that penetrates the planar portion in the first direction,
The bus bar is
a connection path portion extending between the first connection object and the second connection object;
an extension portion that extends outward from the connection path portion and is accommodated in the accommodation portion so as to overlap with the first electronic component when viewed from the first direction;
Electrical connection unit. the extension portion has an end of the bus bar at a position overlapping with the first electronic component when viewed from the first direction.
The electrical connection unit according to claim 1 . The bus bar is integrated with the base member by insert molding.
3. The electrical connection unit according to claim 1 or 2. a metal plate facing the base member from the side opposite to the first connection object;
a first heat transfer member disposed between the bus bar and the metal plate;
Further provided with
3. The electrical connection unit according to claim 1 or 2. a second heat transfer member disposed between the extension and the first electronic component;
3. The electrical connection unit according to claim 1 or 2.